A year ago TreeHugger’s Colleen Vanderlinden traded a number of seeds with me. Some of those seeds were for the 'OSU Blue' tomato. Developed by an Oregon State University professor and his team, the 'OSU Blue' tomato contains anthocyanins derived from a gene of wild tomato relative with anthocyanin-containing fruit.
Domestic tomato varieties grown and consumed in the United States do not normally contain anthocyanins. The tomato was developed using conventional breeding techniques to get more antioxidants into our diets.
You can read more about this at the 'OSU Blue' FAQ, and see more picture of the tomato's color at the link above.